ELECTRICAL ENGINEERING- PAGE 9
ELECTRICAL ENGINEERING MCQs- PAGE 9
1. The best suitable material for the heating element is
(a) Tungsten (b) Nichrome (c) Manganin (d) Carbon
Ans: B
2. Pure silicon is
(a) a p-type semiconductor (b) an n-type semiconductor (c) an intrinsic semiconductor (d) an extrinsic semiconductor
Ans: C
3. Impurity atoms to be added to pure silicon in order to make a p-type semiconductor belongs to
(a) Phosphorous (b) Boron (c) Antimony (d) Aluminium
Ans: B
4. Resistivity of a wire depends upon
(a) Material (b) Area (c) Length (d) All of these
Ans: A
5. If a ferromagnetic material is heated upto Curie temperature, it becomes
(a) Permanent magnet (b) Anti-ferromagnetic material (c) Diamagnetic material (d) Paramagnetic material
Ans: D
6. At absolute zero temperature, an intrinsic semiconductor behaves as
(a) a good conductor (b) a super conductor (c) an insulator (d) variable resistor
Ans: C
7. In an intrinsic semiconductor the Fermi level is
(a) closer to valence band. (b) closer to conduction band.
(c) within the balance band. (d) midway between the valence and conduction bands.
Ans: D
8. The reluctance offered by a magnetic material is highest when it is
(a) Diamagnetic (b) Paramagnetic (c) Ferromagnetic (d) None of these
Ans: A
9. If temperature of a pure silicon specimen is increased, then
(a) only number of free electrons increase. (b) only number of free holes increase.
(c) number of free holes and free electrons increases. (d) only number of free holes decrease.
Ans: C
10. Varnishes protect the insulating materials against
(a) dust and oil (b) moisture, dirt and oil (c) moisture and fire hazards (d) None of the above
Ans: B
11. If a 220 V heater is used on 110 V supply, the heat produced by it will be nearly
(a) one half (b) twice (c) one-fourth (d) four times
Ans: C
12. A VTVM can be used to measure
(a) dc voltage only (b) ac voltage only (c) both (a) and (b) (d) None of the above Ans: C
13. The reactance offered by a capacitor to an alternating current of frequency 50 Hz is 10 ohm. If frequency is increased to 100 Hz, the reactance will be
(a) 2.5 ohm (b) 5.0 ohm (c) 20.0 ohm (d) 40.0 ohm
Ans: B
14. If a dynamometer wattmeter is connected in an ac circuit, the power indicated by the wattmeter will be
(a) volt-ampere product (b) average power (c) peak power (d) instantaneous power
Ans: B
15. The Maxwell bridge is used for measuring
(a) Capacitance (b) Dielectric loss (c) Inductance (d) Phase angle
Ans: C
16. A compensated wattmeter has its reading corrected for error due to
(a) Frequency (b) Friction (c) Power consumed in current coil (d) Power consumed in pressure coil
Ans: D
17. A null type of instrument as compared to a deflecting type instrument has
(a) higher accuracy (b) lower sensitivity (c) faster response (d) All of the above
Ans: A
18. A digital voltmeter has a read-out range from 0 to 9999 counts. When full scale reading is 9.999 V, the resolution of the instrument will be
(a) 100 mV (b) 99 mV (c) 9 mV (d) 1 mV
Ans: D
19. The capacity of a battery is measured in
(a) Watts (b) Watt-hours (c) Amperes (d) Ampere-hours
Ans: D
20. If both the number of turns and core length of an inductive coil are doubled, then its self inductance will be
(a) halved (b) doubled (c) quadrupled (d) unaffected
Ans: B
21. Mutual inductance between two magnetically coupled coils depends on
(a) number of turns only (b) permeability of the core only (c) cross-sectional area of their common core only (d) All of the above
Ans: D
22. Megger is used to measure
(a) very high resistance or insulation resistance. (b) low resistance. (c) high resistance. (d) very low resistance. Ans: A
23. For an RLC series AC circuit, the current at series resistance is
(a) maximum at lagging power factor (b) maximum at leading power factor
(c) maximum at unity power factor (d) minimum at unity power factor
Ans: C
24. If v = (a + jb) and i = (c + jd), then active power is given by
(a) ac + ad (b) ac + bd (c) bc – bd (d) ad + bc
Ans: B
25. While measuring power in a three phase load by two wattmeter method, the reading of two wattmeter are equal and opposite, when (a) load is balanced (b) power factor is unity (c) phase angle is between 60° to 90° (d) the load is purely inductive Ans: D
26. If a capacitance is charged by a square wave current source, then the voltage across the capacitor will be
(a) Square wave (b) Step function (c) Triangular wave (d) Zero
Ans: C
27. In a particular meter, the deflecting torque is directly proportional to the current flowing through it, the type of meter is
(a) moving coil (b) moving iron (c) induction (d) electro-static
Ans: A
28. For measurement of low resistance, the bridge used is
(a) Wheatstone (b) Kelvin (c) Maxwell (d) Anderson
Ans: B
29. The output voltage of a battery drops from 100 V with zero load current to 80 V when load current is 2 A. The internal resistance of the battery is
(a) 10 Ω (b) 20 Ω (c) 40 Ω (d) 50 Ω
Ans: A
30. A charge of 0.1 coulomb moves through a given point in every 0.05 seconds. The current flowing through the point is
(a) 2 mA (b) 5 mA (c) 2 A (d) 5 A
Ans: C
31. Which of the following capacitors are used in D.C. circuits ?
(a) Mica (b) Air (c) Ceramic (d) Electrolytic
Ans: D
32. Internal resistance of a micro-ammeter is 500 ohm. Shunt resistance required to increase its range from 0-100 µA to 0-10 A will be approximately
(a) 0.05 Ω (b) 0.005 Ω (c) 0.5 Ω (d) 5.0 Ω
Ans: B
33. Hay bridge is suitable for measuring following type of inductance
(a) having Q greater than 10. (b) having Q less than 10. (c) having any value of Q. (d) having phase angle of reactance very large.
Ans: A
34. The dielectric loss of a capacitance can be measured by
(a) Hay bridge (b) Maxwell bridge (c) Anderson bridge (d) Schering bridge
Ans: D
35. The capacitance of a capacitor is not affected by
(a) Plate area (b) Plate separation (c) Nature of dielectric (d) Plate thickness
Ans: D
36. A 220 V, 200 W bulb and a 220 V, 100 W bulb are connected in series across a 220 V supply, the power consumed by them will be
(a) 33.3 W (b) 66.6 W (c) 100 W (d) 300 W
Ans: B
37. The direction of inducted e.m.f. can be found with the help of
(a) Fleming’s right hand rule (b) Kirchhoff’s voltage law (c) Lenz’s law (d) Laplace’s law
Ans: C
38. If 1 ampere current is flowing through a 100 mH coil, then energy stored in the coil is
(a) 0.05 Joules (b) 0.5 Joules (c) 5.0 Joules (d) None of these
Ans: A
39. Series resistance required to read 0-250 V with a moving coil instrument of internal resistance 2 ohm and full scale deflection of 50 mA is
(a) 49998 Ω (b) 4998 Ω (c) 498 Ω (d) 49.8 Ω
Ans: B
40. Which of the following is not a method of resistance measurement ?
(a) Ammeter – Voltmeter method (b) Post – Office box method (c) Ohm – Meter method (d) Two wattmeter method
Ans: D
41. Two heater wires of equal length are connected first in series and then in parallel. The ratio of heat generated from series to parallel connection will be
(a) 4 : 1 (b) 2 : 1 (c) 1 : 2 (d) 1 : 4
Ans: D
42. When the current in a coil is increased from 2 A to 4 A in 0.05 seconds, the e.m.f. induced in the coil is 8 V. The self inductance of the coil is
(a) 0.8 H (b) 0.4 H (c) 0.2 H (d) 0.1 H
Ans: C
43. The induced e.m.f. will be maximum when a conductor cuts the magnetic field at an angle of
(a) 15° (b) 30° (c) 45° (d) 90°
Ans: D
44. A delta connected load with resistance of 6 ohm and inductive reactance of 8 ohm in each phase is supplied by a 3-phase, 400 V, 50 Hz, AC supply. The value of total power drawn by the load is
(a) 28.8 kW (b) 14.0 kW (c) 10.8 kW (d) 52.0 kW
Ans: A
45. The frequency of voltage generated in a 4-pole alternator rotating at 1800 r.p.m. is
(a) 25 Hz (b) 30 Hz (c) 60 Hz (d) None of these
Ans: C
46. A 50 Hz alternator will run at the highest speed if it is wound for
(a) 8 poles (b) 6 poles (c) 4 poles (d) 2 poles
Ans: D
47. A transformer having 1000 turns in primary winding is connected to a single phase 250 V a.c. supply. For inducing 400 V in secondary winding, the number of turns in secondary winding must be
(a) 1600 (b) 1250 (c) 400 (d) 250
Ans: A
48. The field poles and armature core of a d.c. generator are laminated in order to reduce
(a) Hysteresis loss (b) Eddy current loss (c) Weight (d) Speed
Ans: B
49. Which one of the following methods gives voltage regulation higher than the actual value in an alternator ?
(a) ZPF method (b) mmf method (c) emf method (d) ASA method
Ans: C
50. If speed of a d.c. shunt motor is increased above the rated speed, then the counter e.m.f.
(a) increases (b) decreases (c) remains unchanged (d) first increases and then decreases
Ans: C
(a) Tungsten (b) Nichrome (c) Manganin (d) Carbon
Ans: B
2. Pure silicon is
(a) a p-type semiconductor (b) an n-type semiconductor (c) an intrinsic semiconductor (d) an extrinsic semiconductor
Ans: C
3. Impurity atoms to be added to pure silicon in order to make a p-type semiconductor belongs to
(a) Phosphorous (b) Boron (c) Antimony (d) Aluminium
Ans: B
4. Resistivity of a wire depends upon
(a) Material (b) Area (c) Length (d) All of these
Ans: A
5. If a ferromagnetic material is heated upto Curie temperature, it becomes
(a) Permanent magnet (b) Anti-ferromagnetic material (c) Diamagnetic material (d) Paramagnetic material
Ans: D
6. At absolute zero temperature, an intrinsic semiconductor behaves as
(a) a good conductor (b) a super conductor (c) an insulator (d) variable resistor
Ans: C
7. In an intrinsic semiconductor the Fermi level is
(a) closer to valence band. (b) closer to conduction band.
(c) within the balance band. (d) midway between the valence and conduction bands.
Ans: D
8. The reluctance offered by a magnetic material is highest when it is
(a) Diamagnetic (b) Paramagnetic (c) Ferromagnetic (d) None of these
Ans: A
9. If temperature of a pure silicon specimen is increased, then
(a) only number of free electrons increase. (b) only number of free holes increase.
(c) number of free holes and free electrons increases. (d) only number of free holes decrease.
Ans: C
10. Varnishes protect the insulating materials against
(a) dust and oil (b) moisture, dirt and oil (c) moisture and fire hazards (d) None of the above
Ans: B
11. If a 220 V heater is used on 110 V supply, the heat produced by it will be nearly
(a) one half (b) twice (c) one-fourth (d) four times
Ans: C
12. A VTVM can be used to measure
(a) dc voltage only (b) ac voltage only (c) both (a) and (b) (d) None of the above Ans: C
13. The reactance offered by a capacitor to an alternating current of frequency 50 Hz is 10 ohm. If frequency is increased to 100 Hz, the reactance will be
(a) 2.5 ohm (b) 5.0 ohm (c) 20.0 ohm (d) 40.0 ohm
Ans: B
14. If a dynamometer wattmeter is connected in an ac circuit, the power indicated by the wattmeter will be
(a) volt-ampere product (b) average power (c) peak power (d) instantaneous power
Ans: B
15. The Maxwell bridge is used for measuring
(a) Capacitance (b) Dielectric loss (c) Inductance (d) Phase angle
Ans: C
16. A compensated wattmeter has its reading corrected for error due to
(a) Frequency (b) Friction (c) Power consumed in current coil (d) Power consumed in pressure coil
Ans: D
17. A null type of instrument as compared to a deflecting type instrument has
(a) higher accuracy (b) lower sensitivity (c) faster response (d) All of the above
Ans: A
18. A digital voltmeter has a read-out range from 0 to 9999 counts. When full scale reading is 9.999 V, the resolution of the instrument will be
(a) 100 mV (b) 99 mV (c) 9 mV (d) 1 mV
Ans: D
19. The capacity of a battery is measured in
(a) Watts (b) Watt-hours (c) Amperes (d) Ampere-hours
Ans: D
20. If both the number of turns and core length of an inductive coil are doubled, then its self inductance will be
(a) halved (b) doubled (c) quadrupled (d) unaffected
Ans: B
21. Mutual inductance between two magnetically coupled coils depends on
(a) number of turns only (b) permeability of the core only (c) cross-sectional area of their common core only (d) All of the above
Ans: D
22. Megger is used to measure
(a) very high resistance or insulation resistance. (b) low resistance. (c) high resistance. (d) very low resistance. Ans: A
23. For an RLC series AC circuit, the current at series resistance is
(a) maximum at lagging power factor (b) maximum at leading power factor
(c) maximum at unity power factor (d) minimum at unity power factor
Ans: C
24. If v = (a + jb) and i = (c + jd), then active power is given by
(a) ac + ad (b) ac + bd (c) bc – bd (d) ad + bc
Ans: B
25. While measuring power in a three phase load by two wattmeter method, the reading of two wattmeter are equal and opposite, when (a) load is balanced (b) power factor is unity (c) phase angle is between 60° to 90° (d) the load is purely inductive Ans: D
26. If a capacitance is charged by a square wave current source, then the voltage across the capacitor will be
(a) Square wave (b) Step function (c) Triangular wave (d) Zero
Ans: C
27. In a particular meter, the deflecting torque is directly proportional to the current flowing through it, the type of meter is
(a) moving coil (b) moving iron (c) induction (d) electro-static
Ans: A
28. For measurement of low resistance, the bridge used is
(a) Wheatstone (b) Kelvin (c) Maxwell (d) Anderson
Ans: B
29. The output voltage of a battery drops from 100 V with zero load current to 80 V when load current is 2 A. The internal resistance of the battery is
(a) 10 Ω (b) 20 Ω (c) 40 Ω (d) 50 Ω
Ans: A
30. A charge of 0.1 coulomb moves through a given point in every 0.05 seconds. The current flowing through the point is
(a) 2 mA (b) 5 mA (c) 2 A (d) 5 A
Ans: C
31. Which of the following capacitors are used in D.C. circuits ?
(a) Mica (b) Air (c) Ceramic (d) Electrolytic
Ans: D
32. Internal resistance of a micro-ammeter is 500 ohm. Shunt resistance required to increase its range from 0-100 µA to 0-10 A will be approximately
(a) 0.05 Ω (b) 0.005 Ω (c) 0.5 Ω (d) 5.0 Ω
Ans: B
33. Hay bridge is suitable for measuring following type of inductance
(a) having Q greater than 10. (b) having Q less than 10. (c) having any value of Q. (d) having phase angle of reactance very large.
Ans: A
34. The dielectric loss of a capacitance can be measured by
(a) Hay bridge (b) Maxwell bridge (c) Anderson bridge (d) Schering bridge
Ans: D
35. The capacitance of a capacitor is not affected by
(a) Plate area (b) Plate separation (c) Nature of dielectric (d) Plate thickness
Ans: D
36. A 220 V, 200 W bulb and a 220 V, 100 W bulb are connected in series across a 220 V supply, the power consumed by them will be
(a) 33.3 W (b) 66.6 W (c) 100 W (d) 300 W
Ans: B
37. The direction of inducted e.m.f. can be found with the help of
(a) Fleming’s right hand rule (b) Kirchhoff’s voltage law (c) Lenz’s law (d) Laplace’s law
Ans: C
38. If 1 ampere current is flowing through a 100 mH coil, then energy stored in the coil is
(a) 0.05 Joules (b) 0.5 Joules (c) 5.0 Joules (d) None of these
Ans: A
39. Series resistance required to read 0-250 V with a moving coil instrument of internal resistance 2 ohm and full scale deflection of 50 mA is
(a) 49998 Ω (b) 4998 Ω (c) 498 Ω (d) 49.8 Ω
Ans: B
40. Which of the following is not a method of resistance measurement ?
(a) Ammeter – Voltmeter method (b) Post – Office box method (c) Ohm – Meter method (d) Two wattmeter method
Ans: D
41. Two heater wires of equal length are connected first in series and then in parallel. The ratio of heat generated from series to parallel connection will be
(a) 4 : 1 (b) 2 : 1 (c) 1 : 2 (d) 1 : 4
Ans: D
42. When the current in a coil is increased from 2 A to 4 A in 0.05 seconds, the e.m.f. induced in the coil is 8 V. The self inductance of the coil is
(a) 0.8 H (b) 0.4 H (c) 0.2 H (d) 0.1 H
Ans: C
43. The induced e.m.f. will be maximum when a conductor cuts the magnetic field at an angle of
(a) 15° (b) 30° (c) 45° (d) 90°
Ans: D
44. A delta connected load with resistance of 6 ohm and inductive reactance of 8 ohm in each phase is supplied by a 3-phase, 400 V, 50 Hz, AC supply. The value of total power drawn by the load is
(a) 28.8 kW (b) 14.0 kW (c) 10.8 kW (d) 52.0 kW
Ans: A
45. The frequency of voltage generated in a 4-pole alternator rotating at 1800 r.p.m. is
(a) 25 Hz (b) 30 Hz (c) 60 Hz (d) None of these
Ans: C
46. A 50 Hz alternator will run at the highest speed if it is wound for
(a) 8 poles (b) 6 poles (c) 4 poles (d) 2 poles
Ans: D
47. A transformer having 1000 turns in primary winding is connected to a single phase 250 V a.c. supply. For inducing 400 V in secondary winding, the number of turns in secondary winding must be
(a) 1600 (b) 1250 (c) 400 (d) 250
Ans: A
48. The field poles and armature core of a d.c. generator are laminated in order to reduce
(a) Hysteresis loss (b) Eddy current loss (c) Weight (d) Speed
Ans: B
49. Which one of the following methods gives voltage regulation higher than the actual value in an alternator ?
(a) ZPF method (b) mmf method (c) emf method (d) ASA method
Ans: C
50. If speed of a d.c. shunt motor is increased above the rated speed, then the counter e.m.f.
(a) increases (b) decreases (c) remains unchanged (d) first increases and then decreases
Ans: C
51. The open current test in a transformer gives
(a) iron losses (b) copper losses (c) friction losses (d) total losses
Ans: A
52. A balanced modulator is used for generation of which of the following ?
(a) DSB-SC signal (b) FM signal (c) PM signal (d) PAM signal
Ans: A
53. An operational amplifier has a differential gain of 100 and a common mode gain of 0.01. Its CMRR will be
(a) 20 dB (b) 40 dB (c) 60 dB (d) 80 dB
Ans: D
54. The full scale output of an 8 bit DAC for 0 to 10 V range is
(a) 1.961 V (b) 9.961 V (c) 96.11 V (d) 1.996 V
Ans: B
55. Memory range of a memory chip 1 K is
(a) 0000H to 03FFH (b) 0001H to 01FFH (c) 0000H to 02FFH (d) 0000H to 04FFH
Ans: A
56. The basic memory cell in a DRAM is a
(a) MOSFET (b) Capacitor (c) Capacitor and a MOS switch (d) Flip-Flop
Ans: C
57. Absorption of radio waves in atmosphere depends on
(a) frequency of waves (b) distance from transmitter (c) polarisation of waves (d) polarisation of atmosphere
Ans: A
58. Each flip-flop in a 4-bit ripple counter introduces a maximum delay of 40 n sec. The maximum clock frequency is
(a) 2.65 MHz (b) 6.25 MHz (c) 5.26 MHz (d) 6.52 MHz
Ans: B
59. Which IC is a decade counter ?
(a) 7476 (b) 7486 (c) 7404 (d) 7490
Ans: D
60. Consider following gates : 1. NAND 2. NOR 3. XOR Out of these gates, the universal gates are
(a) 1 and 3 only (b) 2 and 3 only (c) 1 and 2 only (d) 1, 2 and 3
Ans: C
61. How many flip-flops are required to build a binary counter circuit to count from 0 to 1023 ?
(a) 1 (b) 6 (c) 10 (d) 23
Ans: C
62. Which of the following are 3 byte instruction set ?
(a) MV 1A, 32 H (b) JMP 2085 H (c) MOV C, A (d) ADD B
Ans: B
63. Which of the following oscillators is used for generation of high frequency signal ?
(a) RC phase shift oscillator (b) Blocking oscillator (c) Wein bridge oscillator (d) L-C oscillator
Ans: D
64. In a positive edge triggered JK flip-flop, J = 1, K = 0 and clock pulse is rising, Q will be
(a) 0 (b) 1 (c) showing no change (d) toggle
Ans: B
65. Kaplan turbines are used whenever the water head is
(a) low (b) high (c) medium (d) (b) and (c)
Ans: A
66. The cost of fuel transportation is minimum in
(a) Steam power plant (b) Diesel power plant (c) Hydro-electric plant (d) Coal based power plant
Ans: C
67. Economisers are used to heat
(a) Coal (b) Air (c) Steam (d) Feed water
Ans: D
68. In thermal power plants, the pressure of working fluid cycle is developed by
(a) Condenser (b) Superheater (c) Feed water pump (d) Turbine
Ans: C
69. A gas turbine power plant is best suited for (a) base load (b) peak load (c) emergency purpose (d) None of the above
Ans: B
70. Out of the following plant categories :
(i) Nuclear (ii) Run-off river (iii) Pump storage (iv) Diesel
The base load power plants are
(a) (i) and (ii) (b) (ii) and (iii) (c) (i), (ii) and (iii) (d) (i), (iii) and (iv)
Ans: A
71. Which of the following components is not a part of hydro-electric plant ?
(a) Penstock (b) Spillway (c) Surge tank (d) Economiser
Ans: D
72. Which one is not a commonly used coolant for fast breeder reactor ?
(a) Water (b) Liquid metal (c) Helium (d) Carbon dioxide
Ans: A
73. Combined cycle power plants may need
(a) MHD generator (b) Thermionic converter (c) Thermoelectric generator (d) All of the above
Ans: D
74. The pH value of water used for boiler of thermal power plant is
(a) unity (b) 7 (c) slightly more than 7 (d) 10
Ans: C
75. A cable has inductance of 0.22 mH per kilometer and capacitance of 0.202 µF per kilometer. The surge impedance of the cable is
(a) 50 Ω (b) 42 Ω (c) 33 Ω (d) 28 Ω
Ans: C
76. The first nuclear power plant was built in India at which place ?
(a) Tarapur (b) Rana Pratap Sagar (c) Kalpakkam (d) Narora
Ans: A
77. The economic size of a conductor in transmission and distribution lines of electric power is decided by
(a) Ohm’s law (b) Kelvin’s law (c) Kirchhoff’s law(d) Faraday’s law
Ans: B
78. Which alternator will have more number of poles ?
(a) coupled to steam turbine (b) coupled to gas turbine (c) coupled to hydraulic turbine (d) None of the above
Ans: C
79. In an AC transmission line difference in phase of voltage at two ends of the line is due to
(a) System voltage (b) Insulators (c) Resistance of line (d) Reactance of line
Ans: D
80. If 5000 kW power is transmitted at 220 kV in place of 11 kV, reduction in the value of electric current will be
(a) 90% (b) 95% (c) 5% (d) 10%
Ans: B
81. In long AC transmission lines, the receiving end voltage becomes greater than sending end voltage at light load or no load operation. This is due to
(a) Ferranti effect (b) Skin effect (c) Proximity effect (d) Corona effect
Ans: A
82. For extra high voltage ac transmission lines, conductors used are
(a) All aluminium (b) All steel (c) AAAC (d) ACSR
Ans: D
83. Which of the following is used for power factor improvement in transmission line ?
(a) Three phase induction (b) An overexcited three phase synchronous motor running on no load
(c) Three phase AC series motor (d) Choke
Ans: B
84. The connected load of a consumer is 2 kW and his maximum demand is 1.5 kW. The load factor of the consumer is
(a) 0.375 (b) 0.75 (c) 1.33 (d) None of these
Ans: D
85. If diameter of each conductor of a transmission line is ‘d’, then the diameter of n-layer stranded conductor will be
(a) (2n – 1) d (b) (2n + 1) d (c) (3n – 1) d (d) (3n + 1) d
Ans: B
86. The bundled conductor in EHV transmission line system provides
(a) increased inductance (b) reduced capacitance (c) increased capacitance (d) increased voltage gradient
Ans: C
87. Corona losses in transmission lines are minimized when
(a) conductor size is reduced. (b) smooth conductor is used.
(c) sharp points are provided in the line. (d) current density in conductor is reduced.
Ans: B
88. The power loss in a transmission line depends on
(a) current in the line. (b) resistance of the line. (c) length of the line. (d) All of the above
Ans: D
89. The main consideration for operating transmission line at high voltage is
(a) to increase efficiency only. (b) to reduce power loss only. (c) to increase power transmission capability only. (d) All of the above
Ans: D
90. The presence of earth in case of overhead transmission line
(a) increases capacitance (b) increases inductance (c) decreases capacitance (d) decreases inductance
Ans: A
91. Effect of increase in temperature in an overhead transmission line is
(a) to increase stress and length both (b) to decrease stress and length both
(c) to decrease stress and increase length (d) None of the above
Ans: C
92. A 0-10 A ammeter has a guaranteed accuracy of 1% of full scale deflection, the limiting error while reading 2.5 A will be
(a) 1% (b) 2% (c) 4% (d) None of these
Ans: C
(a) iron losses (b) copper losses (c) friction losses (d) total losses
Ans: A
52. A balanced modulator is used for generation of which of the following ?
(a) DSB-SC signal (b) FM signal (c) PM signal (d) PAM signal
Ans: A
53. An operational amplifier has a differential gain of 100 and a common mode gain of 0.01. Its CMRR will be
(a) 20 dB (b) 40 dB (c) 60 dB (d) 80 dB
Ans: D
54. The full scale output of an 8 bit DAC for 0 to 10 V range is
(a) 1.961 V (b) 9.961 V (c) 96.11 V (d) 1.996 V
Ans: B
55. Memory range of a memory chip 1 K is
(a) 0000H to 03FFH (b) 0001H to 01FFH (c) 0000H to 02FFH (d) 0000H to 04FFH
Ans: A
56. The basic memory cell in a DRAM is a
(a) MOSFET (b) Capacitor (c) Capacitor and a MOS switch (d) Flip-Flop
Ans: C
57. Absorption of radio waves in atmosphere depends on
(a) frequency of waves (b) distance from transmitter (c) polarisation of waves (d) polarisation of atmosphere
Ans: A
58. Each flip-flop in a 4-bit ripple counter introduces a maximum delay of 40 n sec. The maximum clock frequency is
(a) 2.65 MHz (b) 6.25 MHz (c) 5.26 MHz (d) 6.52 MHz
Ans: B
59. Which IC is a decade counter ?
(a) 7476 (b) 7486 (c) 7404 (d) 7490
Ans: D
60. Consider following gates : 1. NAND 2. NOR 3. XOR Out of these gates, the universal gates are
(a) 1 and 3 only (b) 2 and 3 only (c) 1 and 2 only (d) 1, 2 and 3
Ans: C
61. How many flip-flops are required to build a binary counter circuit to count from 0 to 1023 ?
(a) 1 (b) 6 (c) 10 (d) 23
Ans: C
62. Which of the following are 3 byte instruction set ?
(a) MV 1A, 32 H (b) JMP 2085 H (c) MOV C, A (d) ADD B
Ans: B
63. Which of the following oscillators is used for generation of high frequency signal ?
(a) RC phase shift oscillator (b) Blocking oscillator (c) Wein bridge oscillator (d) L-C oscillator
Ans: D
64. In a positive edge triggered JK flip-flop, J = 1, K = 0 and clock pulse is rising, Q will be
(a) 0 (b) 1 (c) showing no change (d) toggle
Ans: B
65. Kaplan turbines are used whenever the water head is
(a) low (b) high (c) medium (d) (b) and (c)
Ans: A
66. The cost of fuel transportation is minimum in
(a) Steam power plant (b) Diesel power plant (c) Hydro-electric plant (d) Coal based power plant
Ans: C
67. Economisers are used to heat
(a) Coal (b) Air (c) Steam (d) Feed water
Ans: D
68. In thermal power plants, the pressure of working fluid cycle is developed by
(a) Condenser (b) Superheater (c) Feed water pump (d) Turbine
Ans: C
69. A gas turbine power plant is best suited for (a) base load (b) peak load (c) emergency purpose (d) None of the above
Ans: B
70. Out of the following plant categories :
(i) Nuclear (ii) Run-off river (iii) Pump storage (iv) Diesel
The base load power plants are
(a) (i) and (ii) (b) (ii) and (iii) (c) (i), (ii) and (iii) (d) (i), (iii) and (iv)
Ans: A
71. Which of the following components is not a part of hydro-electric plant ?
(a) Penstock (b) Spillway (c) Surge tank (d) Economiser
Ans: D
72. Which one is not a commonly used coolant for fast breeder reactor ?
(a) Water (b) Liquid metal (c) Helium (d) Carbon dioxide
Ans: A
73. Combined cycle power plants may need
(a) MHD generator (b) Thermionic converter (c) Thermoelectric generator (d) All of the above
Ans: D
74. The pH value of water used for boiler of thermal power plant is
(a) unity (b) 7 (c) slightly more than 7 (d) 10
Ans: C
75. A cable has inductance of 0.22 mH per kilometer and capacitance of 0.202 µF per kilometer. The surge impedance of the cable is
(a) 50 Ω (b) 42 Ω (c) 33 Ω (d) 28 Ω
Ans: C
76. The first nuclear power plant was built in India at which place ?
(a) Tarapur (b) Rana Pratap Sagar (c) Kalpakkam (d) Narora
Ans: A
77. The economic size of a conductor in transmission and distribution lines of electric power is decided by
(a) Ohm’s law (b) Kelvin’s law (c) Kirchhoff’s law(d) Faraday’s law
Ans: B
78. Which alternator will have more number of poles ?
(a) coupled to steam turbine (b) coupled to gas turbine (c) coupled to hydraulic turbine (d) None of the above
Ans: C
79. In an AC transmission line difference in phase of voltage at two ends of the line is due to
(a) System voltage (b) Insulators (c) Resistance of line (d) Reactance of line
Ans: D
80. If 5000 kW power is transmitted at 220 kV in place of 11 kV, reduction in the value of electric current will be
(a) 90% (b) 95% (c) 5% (d) 10%
Ans: B
81. In long AC transmission lines, the receiving end voltage becomes greater than sending end voltage at light load or no load operation. This is due to
(a) Ferranti effect (b) Skin effect (c) Proximity effect (d) Corona effect
Ans: A
82. For extra high voltage ac transmission lines, conductors used are
(a) All aluminium (b) All steel (c) AAAC (d) ACSR
Ans: D
83. Which of the following is used for power factor improvement in transmission line ?
(a) Three phase induction (b) An overexcited three phase synchronous motor running on no load
(c) Three phase AC series motor (d) Choke
Ans: B
84. The connected load of a consumer is 2 kW and his maximum demand is 1.5 kW. The load factor of the consumer is
(a) 0.375 (b) 0.75 (c) 1.33 (d) None of these
Ans: D
85. If diameter of each conductor of a transmission line is ‘d’, then the diameter of n-layer stranded conductor will be
(a) (2n – 1) d (b) (2n + 1) d (c) (3n – 1) d (d) (3n + 1) d
Ans: B
86. The bundled conductor in EHV transmission line system provides
(a) increased inductance (b) reduced capacitance (c) increased capacitance (d) increased voltage gradient
Ans: C
87. Corona losses in transmission lines are minimized when
(a) conductor size is reduced. (b) smooth conductor is used.
(c) sharp points are provided in the line. (d) current density in conductor is reduced.
Ans: B
88. The power loss in a transmission line depends on
(a) current in the line. (b) resistance of the line. (c) length of the line. (d) All of the above
Ans: D
89. The main consideration for operating transmission line at high voltage is
(a) to increase efficiency only. (b) to reduce power loss only. (c) to increase power transmission capability only. (d) All of the above
Ans: D
90. The presence of earth in case of overhead transmission line
(a) increases capacitance (b) increases inductance (c) decreases capacitance (d) decreases inductance
Ans: A
91. Effect of increase in temperature in an overhead transmission line is
(a) to increase stress and length both (b) to decrease stress and length both
(c) to decrease stress and increase length (d) None of the above
Ans: C
92. A 0-10 A ammeter has a guaranteed accuracy of 1% of full scale deflection, the limiting error while reading 2.5 A will be
(a) 1% (b) 2% (c) 4% (d) None of these
Ans: C
93. The constant of a given energy meter is 500 revolution/kWh. At the test 4.4 kW full load, meter completes 50 revolutions in 86 seconds. The percentage error of the meter is
(a) –4.86% (b) 4.86% (c) 2.0% (d) 3.0%
Ans: A
94. The most efficient form of damping employed in electric instruments is
(a) Air friction damping (b) Fluid friction damping (c) Eddy current damping (d) None of the above
Ans: C
95. Which of the following instruments is equally accurate on ac as well as dc circuits ?
(a) PMMC voltmeter (b) Dynamometer wattmeter (c) Moving iron ammeter (d) Induction wattmeter
Ans: B
96. The moving system of an indicating type of electrical instrument is subjected to
(a) a deflecting torque (b) a controlling torque (c) a damping torque (d) All of the above
Ans: D
97. Energy meter runs slowly even if power is not used. This error is called
(a) Speed error (b) Phase error (c) Creeping error (d) None of these
Ans: C
98. The type of instruments used mainly for standardizing instruments in laboratories is
(a) Indicating instrument (b) Integrating instrument (c) Absolute instrument (d) Recording instrument
Ans: C
99. What will happen if a voltmeter is connected like an ammeter in series of the load ?
(a) The meter will burn out.
(b) The measurement will be too high.
(c) The same current will flow as would have been with ammeter in circuit.
(d) There will be almost no current in the circuit.
Ans: D
100. Which of the following devices is used to measure flow in an open channel ?
(a) Venturimeter (b) Rota meter (c) Orifice (d) Pitot tube
Ans: D
(a) –4.86% (b) 4.86% (c) 2.0% (d) 3.0%
Ans: A
94. The most efficient form of damping employed in electric instruments is
(a) Air friction damping (b) Fluid friction damping (c) Eddy current damping (d) None of the above
Ans: C
95. Which of the following instruments is equally accurate on ac as well as dc circuits ?
(a) PMMC voltmeter (b) Dynamometer wattmeter (c) Moving iron ammeter (d) Induction wattmeter
Ans: B
96. The moving system of an indicating type of electrical instrument is subjected to
(a) a deflecting torque (b) a controlling torque (c) a damping torque (d) All of the above
Ans: D
97. Energy meter runs slowly even if power is not used. This error is called
(a) Speed error (b) Phase error (c) Creeping error (d) None of these
Ans: C
98. The type of instruments used mainly for standardizing instruments in laboratories is
(a) Indicating instrument (b) Integrating instrument (c) Absolute instrument (d) Recording instrument
Ans: C
99. What will happen if a voltmeter is connected like an ammeter in series of the load ?
(a) The meter will burn out.
(b) The measurement will be too high.
(c) The same current will flow as would have been with ammeter in circuit.
(d) There will be almost no current in the circuit.
Ans: D
100. Which of the following devices is used to measure flow in an open channel ?
(a) Venturimeter (b) Rota meter (c) Orifice (d) Pitot tube
Ans: D
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